Gwynne Dyer: Rio+20 and mass extinction

The forthcoming United Nations Conference on Sustainable Development in Rio de Janeiro (Rio+20) on June 20 to 22 has brought out the usual warnings of environmental doom. They have been greeted with the usual indifference: after all, there are seven billion of us now, and we’re all still eating. What could possibly go wrong?

The UN Environment Program published its five-year Global Environmental Outlook (GEO-5) saying that significant progress has been made on only four of 90 environmental goals that were adopted at the Rio Earth Summit in 1992. “If current patterns of production and consumption of natural resources prevail, then governments will preside over unprecedented levels of damage and degradation,” warned UNEP head Achim Steiner. Yawn.

Meanwhile, a team of respected scientists warn that life on Earth may be on the way to an irreversible “tipping point”. Sure. Heard that one before, too.

Last week, one of the world’s two leading scientific journals, Nature, published a paper, “Approaching a state shift in Earth’s biosphere,” pointing out that more than 40 percent of the Earth's land is already used for human needs. With the human population set to grow by a further two billion by 2050, that figure could soon exceed 50 percent.

“It really will be a new world, biologically, at that point,” said the paper’s lead author, Anthony Barnofsky, a professor at the University of California, Berkeley. But Barnofsky doesn’t go into the details of what kind of new world it might be. Scientists hardly ever do in public, for fear of being seen as panic-mongers. Besides, it’s a relatively new hypothesis, but it’s a pretty convincing one, and it should be more widely understood. Here’s how bad it could get.

The scientific consensus is that we are still on track for three degrees Celsius of warming (five degrees Fahrenheit) by 2100, but that’s just warming caused by human greenhouse-gas emissions. The problem is that plus-three degrees is well past the point where the major feedbacks kick in: natural phenomena triggered by our warming, like melting permafrost and the loss of Arctic sea-ice cover, that will add to the heating and that we cannot turn off.

The trigger is actually around two degrees Celsius (3.5 degrees Fahrenheit) higher average global temperature. After that we lose control of the process: ending our own carbon-dioxide emissions would no longer be enough to stop the warming. We may end up trapped on an escalator heading up to plus-six degrees Celsius (plus-10.5 degrees Fahrenheit), with no way of getting off. And plus-six degrees Celsius gives you the mass extinction.

There have been five mass extinctions in the past 500 million years, when 50 percent or more of the species then existing on the Earth vanished, but until recently the only people taking any interest in this were paleontologists, not climate scientists. They did wonder what had caused the extinctions, but the best answer they could come up was “climate change”. It wasn’t a very good answer.

Why would a warmer or colder planet kill off all those species? The warming was caused by massive volcanic eruptions dumping huge quantities of carbon dioxide in the atmosphere for tens of thousands of years. But it was very gradual and the animals and plants had plenty of time to migrate to climatic zones that still suited them. (That’s exactly what happened more recently in the Ice Age, as the glaciers repeatedly covered whole continents and then retreated again.)

There had to be a more convincing kill mechanism than that, and the paleontologists found one when they discovered that a giant asteroid struck the planet 65 million years ago, just at the time when the dinosaurs died out in the most recent of the great extinctions. So they went looking for evidence of huge asteroid strikes at the time of the other extinction events. They found none.

What they discovered was that there was indeed major warming at the time of all the other extinctions—and that the warming had radically changed the oceans. The currents that carry oxygen-rich cold water down to the depths shifted so that they were bringing down oxygen-poor warm water instead, and gradually the depths of the oceans became anoxic: the deep waters no longer had any oxygen.

When that happens, the sulfur bacteria that normally live in the silt (because oxygen is poison to them) come out of hiding and begin to multiply. Eventually they rise all the way to the surface over the whole ocean, killing all the oxygen-breathing life. The ocean also starts emitting enormous amounts of lethal hydrogen sulfide gas that destroy the ozone layer and directly poison land-dwelling species. This has happened many times in the Earth’s history.

Don’t let it worry you. We’ll all be safely dead long before it could happen again: the earliest possible date for a mass extinction, assuming that the theory is right and that we continue down our present track with emissions, would be well into the next century.

The only problem is that things like this tend to become inevitable long before they actually happen. Tick, tock.

Comments

We're now using Facebook for comments.

28 Comments

Evil Eye

Jun 8, 2012 at 1:22pm

What may happen is many local wars, fought over water and/or arable lands, some maybe nuclear, such as India and Pakistan. Poorer countries will bear the brunt of climate change and there is a good chance of the mass extinction of coastal peoples or people too poor or not allowed to migrate.

I have read somewhere that a sea rise of about 1 metre, plus increased desertification in Africa may account for the deaths of 1 billion. Even a local nuclear was may achieve 10 million or more depending where the nuclear bursts takes place. An India Pakistan nuclear war could cost over 500,000 deaths over 10 years.

Climate change may not create many deaths at first, but the wars over land and water could cost billions of lives.

Leone

Steven Earl Salmony

Jun 8, 2012 at 5:27pm

This situation is no longer deniable. During my lifetime, many have understood the Global Predicament we are facing now, but only a few 'voices in the wilderness' were willing to speak out loudly and clearly about what everyone can see. It is not a pretty sight. The human community has precipitated a planetary emergency that only humankind is capable of undoing. The present 'Unsustainable Path' has to be abandoned in favor of a "road less travelled by". It is late; there is no time left to waste. Perhaps now we will gather our remarkably abundant, distinctly human resources and respond ably to the daunting, human-induced, global challenges before us, the ones that threaten life as we know it and the integrity of Earth as a fit place for human habitation. Many voices, many more voices are needed for making necessary changes.

Steven Earl Salmony

Jun 8, 2012 at 5:28pm

If we agree to “think globally”, it becomes evident that riveting attention on GROWTH could be a grave mistake because we are denying how economic and population growth in the communities in which we live cannot continue as it has until now. Each village's resources are being dissipated, each town's environment degraded and every city's fitness as place for our children to inhabit is being threatened. To proclaim something like, 'the meat of any community plan for the future is, of course, growth' fails to acknowledge that many villages, towns and cities are already ‘built out’, and also ‘filled in’ with people. If the quality of life we enjoy now is to be maintained for the children, then limits on economic and population growth will have to be set. By so doing, we choose to “act locally" and sustainably.

More economic and population growth are no longer sustainable in many too many places on the surface of Earth because biological constraints and physical limitations are immutably imposed upon ever increasing human consumption, production and population activities of people in many communities where most of us reside. Inasmuch as the Earth is finite with frangible environs, there comes a point at which GROWTH is unsustainable. There is much work to done locally. But that effort cannot reasonably begin without sensibly limiting economic and population growth.

To quote another source, “We face a wide-open opportunity to break with the old ways of doing the town’s business…..” That is a true statement. But the necessary “break with the old ways” of continous economic and population growth is not what is occurring. There is a call for a break with the old ways, but the required changes in behavior are not what is being proposed as we plan for the future. What is being proposed and continues to occur is more of the same, old business-as-usual overconsumption, overproduction and overpopulation activities, the very activities that appear to be growing unsustainbly. More business-as-usual could soon become patently unsustainable, both locally and globally. A finite planet with the size, composition and environs of the Earth and a community with the boundaries, limited resources and wondrous climate of villages, towns and cities where we live may not be able to sustain much longer the economic and population growth that is occurring on our watch. Perhaps necessary changes away from UNSUSTAINABLE GROWTH and toward sustainable lifestyles and right-sized corporate enterprises are in the offing.

Think globally while there is still time and act locally before it is too late for human action to make any difference in the clear and presently dangerous course of unfolding human-induced ecological events, both in our planetary home and in our villages, towns and cities.

Crablady

Jun 9, 2012 at 10:07am

Millions of years of evolution and slowly-accumulated biodiversity will be lost as well as civilization as we know it. Our generation will be the villians in history; we are the rapists and pillagers who would not put the survival of civilization ahead of our short-term and rapacious consumption. I mourn the loss of this wonderfully complex biodiversity by using the number of endangered animals left as my PINs. For example, I have to change tigers from 3500 to 3200 total worldwide. It keeps my security tight since these numbers go down (from only 4 digits) every day for rhinos, panthers, etc. How truly sad.

And more. That means stopping the jobs as we know them, too, guys! If you work for a climate-hostile industry (most of BC's economy) and you want to do the right thing: quit. That's reality. No consumption, no destructive industry, no economic growth: an intentional economic depression to save the planet.

Instead, switch our society to a research and science, nature restoring economy. The goals: how to live sustainably in our environment, and, long term, how to - stay with me here - colonize space. Because we might be able to, by incredibly hard work and a miracle, live sustainably for a few hundred years, but we're too stupid to have all our eggs in one basket.

I wonder how people would take to that? That's what's required. We've got, um, maybe twenty or thirty years to pull it off, at least the foundation (not the space part). I think it's a wash, but worth a try in any case. There's obviously no future in the consumerism our society is organized around anyway, so fuck it.

Ian G62

Jun 9, 2012 at 1:07pm

One of the things [and there are several] that tick me off is the prevalent mode of thought that somehow we can buy our way out of our current situation with "green" products. The contradiction is the raw materials for such products still have to come from some place recycled or otherwise. A serious re-think about how we consume needs to be done - Canada is way behind on this still - courtesy of our federal and provincial gov'ts.

However, for the long term as this article suggests, as climate extremes become prevalent, the fight for the remaining space will become paramount and let's face it fighting with each other is one of the things we do best, our future as a species will be in continually doubt.

We are still far away from collectively thinking globally, the closer we get to that point increases the chance of us surviving OR we can turn it inward and protect what we have and fuck everyone else - that too may work for those that have the biggest stick.

Suzuki minion

Jun 9, 2012 at 1:17pm

Nature's reset button... We have become a lesson in history. A story for future generations. The system that should have never been. A shameful lesson to humanity who will learn about us in an uninvented homoginized language.Meanwhile, some of us who have heard the message loud and clear continue to sweat and bleed in the name of keeping our brothers and sisters on the path of righteousness. Knowledge which will keep a few of us to see the sun rise once more. Our judgement is before us. Make money or make peace.

Edward01ca

Jun 9, 2012 at 5:09pm

I don't want to sound very pessimistic, but I cannot see the developing countries like the BRICS wanting to cut consumption or the degradation of their environments. What we do in Canada for all of our green initiatives will do very little worldwide. I agree with Evil Eye, the wars over resources will only increase dramatically. Right now these wars are over the control of oil, soon it will be water and arable land.